Concealed latch assembly

ABSTRACT

A low cost latch assembly, which cannot be seen from the exterior of a cabinet in which it is used, consisting of an overcenter latch attached to the cabinet and an actuating member attached to the inside of a cabinet door. The over-center latch includes a rotatable latch plate with two perpendicular arms and a spring for biasing the latch plate to extremes of an arc. The actuating member pushes on one perpendicular arm to force the latch plate over center as the door is closed. The second perpendicular arm is rotated into a latching position behind the actuating member. The actuating member also forces the latch plate back over center to an unlatched position as the door is pulled open.

nited States Patent [191 Waltham, Mass.

22 Filed: Mar. 26, 1973 21 A l. No; 344,783

521 u.s.c|....... 292/78 51 int. Cl. E05c 19/02 [58] Field ofSearch 292/78,18, DIG. 49, 70, 292/79, 198,216

[56] References Cited UNITED STATES PATENTS 900,415 10/1908 Nelson 292/78 967,394 8/1910 Lapor.t.... 292/78 1.117949 11/1914 Moyer..... 292/78 3,355,207 11/1967 Newman 292/78 '[11] 3,822,904 Peterson 1 July 9, 1974 CONEALED LATCH ASSEMBLY 3.506292 4/1970 Hagendoorn 292/78 [75] Inventor: g? Peterson Oklahoma Primary Examiner-Robert L. Wolfe Attorney, Agent, or FirmGerald R. Woods; Edwin H. [73] Assignee: Honeywell Information Systems Inc., Crabtree the latch plate over center as the door is closed. The

second perpendicular arm is rotated into a latching position behind the actuating member. The actuating member also forces the latch plate back over center to an unlatched position as the door is pulled open.

6 Claims, 3 Drawing Figures PATENTED JUL 91974 CONCEALED LATCH ASSEMBLY I BACKGROUND OF THE INVENTION The present invention relates'to closures and more particularly to a concealed, low cost latch assembly.

There are many known types of latch assemblies for releasably latching a door to a cabinet or other unit. While known latch assemblies have certain advantages,

they also possess certain disadvantages. A latch assem-.

bly may be low in cost but yet unsatisfactory because it is difficult to adjust or because unsightly parts are visible to one looking at the cabinet. Conversely, concealed latches, while aesthetically satisfactory, may be impractical because of high cost or lack of easy adjustability. I

SUMMARY OF THE INVENTION The present invention is a concealed, low cost latch assembly which requires no adjustments after it has been mounted in a unit and on a door.

The latch assembly includes an over-center latch preferably attached to the unit. The over-center latch includes a latch plate with first and second latch arms, a bracket for the latch plate, and a spring device. The latch plate is mounted in the bracket in a manner which allows the junction of the latch arms to .be rotated through an arc fixed relative to the unit. The spring device biases the latch plate from a neutral center position to either of the two extremes of the arc. The latch assembly also includes an actuating member preferably attached to the door. The first side of the actuating member contacts the first latch arm if the door is moved toward the opening. As a result, the latch plate DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, details of a preferred embodiment of the invention along with its further objects'and advantages may be more readily-ascertained from the following detailed description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a latch assembly constructed in accordance with the present invention;

FIG. 2 is an edge view of the latch assembly of FIG.

' l in an unlatched or open position; and

FIG. 3 is an edge view of the latch assembly of FIG. 1 in the latched or closed position.

DETAILED DESCRIPTION Referring now to FIG. 1, a latch assembly constructed in accordance with the present invention includes two major subassemblies, an over-center latch shown attached to a unit or cabinet l2and an actuating member 14 shown attached to the inside surface of a door 16. The actuating member 14 is an essentially Z-shaped piece of material having a first leg 17 secured to an inside surface of door 16, a second leg 18 which and a third leg 20 which is parallel to but spaced from the inside surface of the door 16. Except for the addition of the actuating member 14, door 16 is a conventional cabinet door preferably hinged to the cabinet 12 and including a flexible bumper 22 to cushion the impact when the other door is closed.

The other major subassembly, over-center latch 10, has a support 24 for rigidly attaching a bracket 26 to an inside surface of the cabinet 12. Bracket 26 is preferably a unitary, U-shaped structure including a bight 28 secured to support 24, a first arm 30 extending into the cabinet 12 from one edge of bight 28 and a second spaced arm 32 extending into cabinet 12 from the other edge of bight 28. The arms 30 and 32 includes openings 34 and" 35, respectively, extending to the rear most edge of the arms 30 and 32 by means of channels 36 and 37, respectively.

The openings 34 and 35 accept projections 38 and 40 on support arms 42 and 44 for a latch plate 46. Latch plate 46, like bracket 26, is preferably fabricated from a single piece of sheet material. Latch plate 46 includes a first latch arm 48 and a second latch arm 50 which, in a preferred embodiment, extends at approximately right angles from the first latch arm 48. As may be seen more clearly by dotted lines in FIGS. 2 and 3, the support anns 42 and 44 extend away from the junction 49 of latch arms 48 and 50 along the line which roughly bisects the larger of the two angles between the latch arms 48 and 50.

Referring again to FIG. 1, a spring device 52, preferably a coil spring, is connected between the junction 49 and a point at the end of a tab 54 at the upper end of bracket 26. Coil spring 52 provides a continuous overcenter force on the latch plate 46, the significance of which is explained with reference to FIGS. 2 and 3.

Referring to FIG. 2, the cabinet 12 and door 16 are shown in an open or unlatched configuration. In this configuration, tension exerted by coil spring 52 on the junction 49 causes the latch plate 46 to be held atone extreme of an are. In this extreme position, one surface of the second latch arm 50 rests against the lower edge of the support 24. The first latch arm 48 extends downwardly roughly parallel to the plane of the opening for the door 16.

As an operator manually moves the door 16 to the right or toward its closedposition, the first or right side of leg 20 contacts the first latch arm 48 forcing the latch plate to the right. The latch plate 46 is forced to rotate about an axis defined by openings '34 and 35. The path of the junction 49 as the latch plate 46 is rotated is the are mentioned earlier. Until a neutral center position is reached, coil spring 52 continues to bias the latch plate 46 in a clockwise direction in opposition to the door closing'force.

After latch plate 46 passes a neutral center position,.

however, the coil spring 52 exerts a counterclockwise force on latch plate 46. Latch arm 48 assumes the horizontal position shown in FIG. 3 in which it extends rearwardly into the cabinet 12. Latch arm 50 is rotated into the vertical position shown in FIG. 3 where it bears against the second side of the leg 20. Further counterclockwise movement of the latch plate 46 is prevented by the contact between the latch arm 50 and the leg 20, which can move no further to the right due to the contact between the support 24 on cabinet 12 and the bumper 22 on door 16. The continuous counterclockwise force of coil spring 52 on the latch arm 46 provides a latching force which holds the door in a closed position when the cabinet 12 is subjected to minor shocks or vibration.

When an operator wants to open door 16, he pulls it toward the left. As the door moves in that direction, leg of actuating member 14 pushes arm 50 of the latch plate 46, causing the latch plate 46 to be rotated in a clockwise direction against the force exerted by coil spring 52. Once the neutral center position is reached, however, coil spring 52 aids the clockwise rotation of latch plate 46 and eventually pulls latch plate 46 into the position shown in FIG. 2 wherein the door 16 is completely concealed within the cabinet except for the small section of support 24 which can be seen at the edge of door 16. Since support 24 preferably extends the full width of the cabinet opening, its visible area is not aesthetically objectionable. More significant, perhaps, is the fact that the described latch assembly consists of a conventional coil spring 52 in combination with bracket 26, support 24, latch plate 46 and actuating member 14. Each of the last four of the listed components can be inexpensively fabricated from a single piece of sheet metal. Since the cost of each of the components in the latch assembly is low and the fabrication of the assembly is simple, the cost of the complete assembly is also low. Also, there is no need to adjust any component of the latch assembly after installation.

While there has been described what is considered to be a preferred embodiment of the invention, variatons and modifications will occur to those skilled in the art once they become familiar with the invention. For example, it would be easy for one skilled in the art to attach an over-center latch subassembly to the inside of a door and an actuating member subassembly to a cabinet ifsuch an arrangement were desirable for some reason. Also, while the over-center latch 10 has been shown having a latch plate which rotates about an axis parallel to the axis of rotation of the door, it should be understood that the over-center latch could be moved from the cabinet surface opposite the hinged edge to a cabinet surface adjacent the hinged edge if the actuating member 14 were also moved. Moreover, it is not necessary that the door be hinged at all. If over-center latches were positioned at opposite edges of a door opening, a completely removable door with appropriately placed actuating members could be used.

THerefore, it is intended that the appended claims shall be construed as including all such variations and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. For use with components such as a door and a unit having an opening, an improved latch assembly includmg:

a. an over-center latch attached to one of the components comprising i. a latch plate having first and second generally perpendicular latch arms and support arms extending from the junction of said latch arms along a line generally bisecting the larger of the two angles between the latch arms,

ii. a bracket for said latch platewhich allows the junction of said latch arms to be rotated through a fixed are relative to said first component,

iii. a spring device for biasing said latch plate from a neutral center position to one of two extremes of the arc; and

b. an actuating member attached to the other of the components.

i. the first side of which contacts the first latch arm as the door is moved toward the opening to rotate the latch plate from a first extreme of the arc over center to a second extreme of the arc whereat the second latch arm bears on the second side of said actuating member, and

ii. the second side of which bears on the second latch arm as the door is moved away from the opening to rotate the latch plate back over center to the first extreme of the arc.

2. An improved latch assembly as recited in claim 1 wherein said bracket includes a bight secured to the unit, a first arm extending from one edge of said bight into the unit and a second parallel arm extending from the other edge of said bight into the unit, said first and second bracket arms having openings for receiving the free ends of the support arms.

3. An improved latch assembly as recited in claim 1 wherein said bracket further includes a tab extending from one end of said bracket in the same direction as the first and second bracket arms, said tab including means for securing one end of said coil spring.

4. An improved latch assembly as recited in claim 2 wherein the smaller angle between the first and second latch arms is approximately 5. An improved latch assembly as recited in claim 4 wherein the angle of the arc through which the latch plate can be rotated is also approximately 90.

6. For use with a cabinet having a hinged door which can be rotated about an axis, an improved latch assembly including:

a. an over-center latch comprising i. a latch plate having first and second generally perpendicular latch arms and support arms extending from the junction of said latch arms along a line generally bisecting the larger of the two angles between the latch arms,

ii. a U-shaped bracket having a bight attached to said cabinet and a pair of parallel arms extending into the cabinet from opposite edges of the bight, each of said parallel arms containing an opening which in combination with the other defines an axis of rotation parallel to the axis of rotation of the cabinet door, said openings receiving said support arms on said latch plate;

iii. a coil spring connected between the junction of the perpendicular latch arms and a point on said U-shaped bracket for biasing said latch plate from a neutral center position toward one of two opposite extremes on an are extending through the neutral position; and

b. an actuating member having a first leg secured to an inside surface of the cabinet door, a second leg connected to the first leg and extending away from the cabinet door and a third leg connected to the second leg and extending parallel to the inside surface of the cabinet door. the actuating member being positioned relative to the over-center latch so that i. a first side of the third leg contacts the first latch arm as the door is moved toward the cabinet and rotates the latch plate over center to an extreme center to an extreme position wherein the actuating member and latch plate are no longer in contact. 

1. For use with components such as a door and a unit having an opening, an improved latch assembly including: a. an over-center latch attached to one of the components comprising i. a latch plate having first and second generally perpendicular latch arms and support arms extending from the junction of said latch arms along a line generally bisecting the larger of the two angles between the latch arms, ii. a bracket for said latch plate which allows the junction of said latch arms to be rotated through a fixed arc relative to said first component, iii. a spring device for biasing said latch plate from a neutral center position to one of two extremes of the arc; and b. an actuating member attached to the other of the components, i. the first side of which contacts the first latch arm as the door is moved toward the opening to rotate the latch plate from a first extreme of the arc over center to a second extreme of the arc whereat the second latch arm bears on the second side of said actuating member, and ii. the second side of which bears on the second latch arm as the door is moved away from the opening to rotate the latch plate back over center to the first extreme of the arc.
 2. An improved latch assembly as recited in claim 1 wherein said bracket includes a bight secured to the unit, a first arm extending from one edge of said bight into the unit and a second parallel arm extending from the other edge of said bight into the unit, said first and second bracket arms having openings for receiving the free ends of the support arms.
 3. An improved latch assembly as recited in claim 1 wherein said bracket further includes a tab extending from one end of said bracket in the same direction as the first and second bracket arms, said tab including means for securing one end of said coil spring.
 4. An improved latch assembly as recited in claim 2 wherein the smaller angle between the first and second latch arms is approximately 90* .
 5. An improved latch assembly as recited in claim 4 wherein the angle of the arc through which the latch plate can be rotated is also approximately 90* .
 6. For use with a cabinet having a hinged door which can be rotated about an axis, an improved latch assembly including: a. an over-center latch comprising i. a latch plate having first and second generally perpendicular latch arms and support arms extending from the junction of said latch arms along a line generally bisecting the larger of the two angles between the latch arms, ii. a U-shaped bracket having a bight attached to said cabinet and a pair of parallel arms extending into the cabinet from opposite edges of the bight, each of said parallel arms containing an opening which in combination with the other defines an axis of rotation parallel to the axis of rotation of the cabinet door, said openings receiving said support arms on said latch plate; iii. a coil spring connected between the junction of the perpendicular latch arms and a point on said U-shaped bracket for biasing said latch plate from a neutral center position toward one of two opposite extremes on an arc extending through the neutral position; and b. an actuating member having a first leg secured to an inside surface of the cabinet door, a second leg connected to the first leg and extending away from the cabinet door and a third leg connected to the second leg and extending parallel to the inside surface of the cabinet door, the actuating member being positioned relative to the over-center latch so that i. a first side of the third leg contacts the first latch arm as the door is moved toward the cabinet and rotates the latch plate over center to an extreme position wherein the second latch arm comes to bear on the second side of the third leg, and ii. the second side of the third leg bears on the second latch arm as the door is moved away from the cabinet to rotate the latch plate back over center to an extreme position wherein the actuating member and latch plate are no longer in contact. 